Based on the Zeiss Sonnar optical concept, this lens uses a design with 11 elements in eight groups that helps achieve the large maximum aperture of f/1.8 while simultaneously reducing flare and improving contrast. A telephoto prime designed for full-frame A-mount cameras, the 135mm can also be used on APS-C camera systems where it will provide a 202.5mm equivalent focal length. The f/1.8 maximum aperture is exceptionally fast for this class of lens, allowing users to create images with shallow depth of field and work in low-light conditions with relative ease.

Zeiss T* anti-reflective coatings have been applied to each lens surface to help minimize reflections in order to provide greater image clarity, contrast, and color fidelity. Two extra-low dispersion glass elements are featured in the lens design to help reduce chromatic aberrations and color fringing for improved clarity and color neutrality. An Auto Clutch mechanism prevents the focusing ring from rotating when the lens is set to autofocus, allowing for easier, and more natural feeling control over the lens. An internal focus design helps optimize the autofocus system for faster, more reliable focusing. A focus hold button is present for intuitive tactile control and rapid access to select settings. Minimum focus distance of 2.4' with a relatively high 0.25x magnification allows shooters to get closer to their subject. Rounded nine-blade diaphragm contributes to a pleasing bokeh quality when employing selective focus techniques.